The present invention relates to power current converter topology and control. More particularly, the invention relates to a new high accuracy control scheme to control the output current of the power current converter, and the power current converter can be used as a controllable current source for several applications, e.g. LED driver and Battery charger.
In existed power current converter control schemes, as power current converter's inductor current running in discontinuous mode (DCM), there is constant power control scheme, that is, as the peak current of the inductor can be controlled, the output power can be controlled.
      P    OUT    =            1      2        ·          f      S        ·    L    ·          I      peak      2      It uses to generate a series of PWM pulses and to control the power switch in the power current converter. It can make the output average current following the preset reference signal. The control scheme makes that the average output accuracy is largely dependent on the input and output voltages of the power current converter, accuracy of circuit devices and switching frequency. In lower accuracy output application, the control scheme has been widely used. To increase control accuracy is a key point to extend the control scheme application area.